o- AND p-NITROriIKNOL
Small pieces of pumice impregnated with a paste of nickel
oxide (NiO) and water is dried on the water-bath and packed into
the wide tube, which is then loosely plugged at each end with
asbestos. The phenol is incited and poured into the distilling flask.
The air-bath is slightly tilted so that any liquid which may collect
in the tube can run down into the receiver. The process is
conducted as follows : the delivery tube from the Kipp is first
raised above the surface of ihc phenol and a slow current of
pure dry hydrogen passed through the apparatus, the tempera-
ture of which is maintained at 300° for 20 minutes. The nickel
oxide is thereby reduced and changes from black to pale yellow.
After reduction, the lemperiture is lowered to 160-170° and
kept at this point. The phenol in the llask is now melted and
heated just below its boiling-point, whilst a fairly rapid current
of hydrogen is passed through the delivery tube, which is
thrust well into the liquid. The hcxahydrophcnol slowly distils
and condenses in the receiver. Care must be taken that the
phenol does not condense in the tube, but that only the vapour
passes over. When sufficient liquid has collected, it is shaken
with caustic soda solution, extracted with ether, dehydrated over
potassium carbonate and distilled.
C,,nf,OII + 6H =CtfHnOH.
Properties.-- Colourless liquid ; b. p. 170° ; pleasant aromatic
smell distinct from phenol; insoluble in water and solutions of
caustic alkalis. See Appendix, p. 295.
o- and p-Nitrophenol, C(iH,,<
•OH i i
Hofmann, AnimlMJ, 1857, 103, 347 ; Fritsche, Aunalen, 1859,
110, 150 ; Kekule, Lehrbitch d. org. chcm., 3, 40.
40 grins, phenol
70 „ (500.0.) cone, nitric acid (in 1700.0. water).
The phenol, melted in a basin on the water-bath, is slowly
added in small quantities to the nitric acid and water contained